The Muskegon County Resource Recovery Center (MCRCC), a vast 11,000-acre water treatment system, required an updated Emergency Action Plan (EAP) to meet federal compliance. This plan included revised maps identifying potential inundation areas for five dam break scenarios, helping authorities respond quickly to minimize damage and protect infrastructure and water resources. The maps detailed inundation boundaries, worst-case flood elevations, and flood arrival times.
To estimate the potential inundation areas, the project team employed the HEC-RAS 2-D model, simulating various dam failure scenarios. Using GIS data, they prepared detailed inundation maps that identified boundaries, worst-case flood elevations, and flood arrival times. The analysis focused on the largest inundation areas and the quickest flood arrival times across five different scenarios to ensure a thorough and effective emergency response plan.
Scenario 1: Most Probable Best-Case Scenario
The East Lagoon experiences a breach at the seepage point, while the West Lagoon remains isolated, with the failure occurring at the lagoon’s lowest depth.
Scenario 2: Most Probable Average-Case Scenario
The West Lagoon breaches at the seepage point, while the East Lagoon remains isolated, with the failure occurring at the lagoon’s average depth.
Scenario 3: Worst-Case Scenario – Terror Attack at Deepest Depth
In an act of terrorism, both lagoons are breached simultaneously—one at the corner of the West Lagoon near the cell phone tower, and the other at the corner of the East Lagoon by the center berm wall. This results in the destruction of the center berm/dike road. The scenario assumes the lagoons are at maximum depth during the breach.
Scenario 4: Most Probable Worst-Case Scenario
The lagoon breaches at the seepage point, while the West Lagoon remains isolated, with the failure occurring at the lagoon’s maximum depth.
Scenario 5: Breach on the North Side of the East Lagoon
The East Lagoon breaches near the South Irrigation Pump Station on the northeast side of the berm, while the West Lagoon remains isolated. The failure occurs with the lagoon at its maximum depth.
Scenarios 1-4 simulated breaches along the southern edge of the MCRCC lagoons, sending floodwaters toward Mona Lake via the Black Creek Drain. Scenario 5 modeled a breach near the East Lagoon, diverting some floodwaters to both the Muskegon River and Black Creek Drain.
Modeling produced comprehensive inundation maps, GIS data, videos, and a detailed summary report, all designed to strengthen the MCRCC’s EAP. These enhancements ensure better preparedness, regulatory compliance, and improved emergency response, while building public trust and maintaining operational continuity—ultimately protecting lives, property, and the environment.